30 degrees will result in an edge that hold up better. I normally use 30
for chopping and 25 for chisels used for paring only.
--
Alan Bierbaum
Web Site: http://www.calanb.com
Current project: http://home.comcast.net/~cabierbaum/
"brian roth" <[email protected]> wrote in message
news:[email protected]...
> What is a good sharpening angle for dovetails, which involve some
> (mild) chopping cuts? Last night I was cleaning up some tenon shoulders
> and my chisels edge didn't seem to hold up well. Wood was white
> oak, and the angle was 25 degrees. Chisels in question are good
> ones (Barr).
brian roth wrote:
> What is a good sharpening angle for dovetails, which involve some
> (mild) chopping cuts? Last night I was cleaning up some tenon shoulders
> and my chisels edge didn't seem to hold up well. Wood was white
> oak, and the angle was 25 degrees. Chisels in question are good
> ones (Barr).
Given the reputation, not to mention price
of Barr chisels, I'm surprised at your report.
Assuming you're talking about the sharpening
angle at the actual cutting edge
(as opposed to grinding, primary and other bevels)
you might go a little higher, but certainly
no higher than 30 degrees (which is what I used
for mortising). If they still don't hold up,
a "conversation" with Mr Barr may lie in your future,
To avoid your question, I'd suggest removing the
bulk of your waste with a fine bladed saw (e.g. coping saw,
small bow saw, or jewellers piercing saw)
and then performing only final paring with
chisels.
BugBear
brian roth wrote:
>
> What is a good sharpening angle for dovetails, which involve some
> (mild) chopping cuts? Last night I was cleaning up some tenon shoulders
> and my chisels edge didn't seem to hold up well. Wood was white
> oak, and the angle was 25 degrees. Chisels in question are good
> ones (Barr).
Am a little confused. The subject line refers to dovetails but
the text is about tenons. The former may involve some chopping
cuts but the latter should be paring/shearing cuts.
Tenon shoulders first:
If you're "cleaning up" tenon shoulders with a bench chisel or two,
you should be making paring cuts, not chopping cuts. The former
are done with only hand pressure and a rocking, shearing motion
rather than a mallet driven square chopped action.
(second set of illustrations on this page show the rocking/shearing
thing. the next page shows an animated version of the idea)
http://home.comcast.net/~charliebcz/DovetailDrawer9B.html
Dovetail socket waste chopping:
If you're chopping the waste between dovetail pins or tails in
oak then Frank Klausz's Three Chop Cuts Per Side (which works
for the pine he prefers to use) probably will kill your chisel's
edge. Less mallet force and more, lighter chopping cuts will
get you there with less chisel wear and tear, though it will
take a little longer. A set of butt chisels sharpened at the
bigger bevel angle may also help. Because they're shorter,
they're easier to position and a shorter tool length means
less torque on the cutting edge if the mallet blow/tap is
not directly down the long axis of the chisel. Lots of subtle
things involved with hand tools and there's a very good
reason for all the "special" versions of hand tools.
Consider using a coping saw to get most of the socket waste
free and then pare the rest. Much easier on the chisels and
with a little practice, just as fast.
hope this helps a bit.
charlie b
AArDvarK wrote:
>
> > The whole .pdf for that: http://home.comcast.net/~charliebcz/DovetailDrawer0.html
> >
>
> Charlie you don't mind if I DL'd the .pdf do you?
> Alex
Not at all. My intent was to get folks to try handcutting dovetails.
If the info I put together gets someone to try it then I'm a happy
camper. And don't overlook the link to the site with a compendium
of dovetailing info.
charlie b
"brian roth" <[email protected]> wrote in message
news:[email protected]...
> What is a good sharpening angle for dovetails, which involve some
> (mild) chopping cuts? Last night I was cleaning up some tenon shoulders
> and my chisels edge didn't seem to hold up well. Wood was white
> oak, and the angle was 25 degrees. Chisels in question are good
> ones (Barr).
I'd think 30 degrees would be better for chopping, 25 for paring.
Your post reminds me of a scene from one of those make over shows I caught a
week or two ago. A guy "borrowed" a chisel and hammer from the carpenter's
tool box without permission. While he was chopping glazing compound out of a
window the carpenter came over angrily and said "tell me you're not using a
$125 chisel to do that..." as he grabbed the chisel from the borrower's
hands and walked away. It was a socket chisel with a band at the top of the
wooden handle... I thought at the time it was a Barr chisel. ;-)
John
> What is a good sharpening angle for dovetails, which involve some
> (mild) chopping cuts? Last night I was cleaning up some tenon shoulders
> and my chisels edge didn't seem to hold up well. Wood was white
> oak, and the angle was 25 degrees. Chisels in question are good
> ones (Barr).
Cripes you actually paid for Barr chisels??? (I think I admire that...)
Alex
> I'd think 30 degrees would be better for chopping, 25 for paring.
> Your post reminds me of a scene from one of those make over shows I caught a
> week or two ago. A guy "borrowed" a chisel and hammer from the carpenter's
> tool box without permission. While he was chopping glazing compound out of a
> window the carpenter came over angrily and said "tell me you're not using a
> $125 chisel to do that..." as he grabbed the chisel from the borrower's
> hands and walked away. It was a socket chisel with a band at the top of the
> wooden handle... I thought at the time it was a Barr chisel. ;-)
Each Barr is hand pounded, awesome. It drives the carbon content closer together
to a more concentrated state, creating serious strength.
Alex